The present invention relates generally to oil, gas and water wells and, more particularly, but without limitation, to products and methods for treating well bores during drilling and completion.
Oil and gas well bores typically are made by drilling down into a formation using rotary-driven drill bits. This process generates cuttings that must be flushed or swept from the well to maximize efficiency of the drilling operation. Conventionally, this sweeping process has been carried out by pouring a liquefied polymer composition down through the drill string. Other well treatments involve the introduction of a treatment composition into the well bore from the surface. For example, sometimes during the drilling process, it is desirable to introduce agents to act as preservatives, caustics, and/or corrosion inhibitors.
Where these treatment chemicals and compositions are liquid, the introduction of the liquid through the drill pipe is often problematic. For example, in the case of liquid polymers, spillage frequently occurs around the rig floor and near the mud pits and the mud pump. This makes the work area hazardous because the liquid is so slippery. Moreover, spillage results in waste. Still further, most of the treatment compositions are introduced using water or other solvents, which reduces the concentration and the efficiency of the compositions.
The present invention comprises a well treatment product for use in a well bore with a treatment solvent. The product comprises a concentrated well treatment composition. The composition is soluble in the solvent to form a circulating solution. The circulating solution formed is characterized by the ability to circulate through the well bore. The product further comprises a container enclosing the composition. The container is sized to be received in the well bore and is at least partially soluble in the solvent to release the composition.
Further, the present invention comprises a method for treating a well bore. The method comprises depositing in the well bore from the surface an effective amount of a treatment composition. The treatment composition is soluble in a selected solvent to form a circulating solution characterized by the ability to circulate through the well bore. When it is deposited, the treatment composition is enclosed in a container that is at least partially soluble in the selected solvent. An effective amount of the selected solvent is deposited in the well bore to dissolve the treatment composition and form the circulating solution. The circulating solution is circulated through the well bore, and a significant portion of the circulating solution is recovered at the surface.
Still further, the present invention includes a system for treating a well bore. The system comprises an elongate conduit sized to be inserted down the well bore. Also included in the system are a solvent, and a container enclosing a treatment composition. The container is sized to be received in the conduit and is characterized by being at least partially soluble in the solvent. The treatment composition is soluble in the solvent to form a circulating solution characterized by the ability to circulate through the well bore.